Agitator bristle tufting design

ABSTRACT

A rotary agitator is provided having a body with an exterior surface. A plurality of bristle tufts extend outwardly from the exterior surface about an arc of less than 360°. A tuftless gap on the exterior surface provides for enhanced bare floor cleaning. The tuftless gap extends through an arc of between about 20° and about 40°. In one particularly useful embodiment two tuftless gaps are provided at opposing positions on the agitator body.

TECHNICAL FIELD OF THE INVENTION

The present invention relates generally to the floor care equipment field and, more particularly, to a rotary agitator incorporating a new bristle tuft pattern including a tuftless gap that enhances the bare floor cleaning efficiency of a vacuum cleaner.

BACKGROUND OF THE INVENTION

Rotary agitators for vacuum cleaners are well known in the art. Many such agitators are provided with projecting bristle tufts wherein the bristle tuft pattern is designed to ensure that at least one bristle tuft is substantially orthogonal with the floor (i.e. at least one bristle tuft is 90° to the plane of the floor F) at any degree of rotation of the agitator body (see FIG. 7). Thus, for example, if the tufted agitator has two helical rows of bristle tufts, each row extends about an arc of substantially 180° so that together the two rows of bristle tufts T₁, T₂ extend fully around a 360° arc of the agitator body B. Examples of such agitator designs are disclosed in, for example, U.S. Pat. Nos. 5,495,634 to Brundula et al and 6,574,823 to Stegens et al.

In contrast to state of the art rotary agitators of this type, the present invention relates to a rotary agitator having a bristle tuft pattern that extends or projects from the exterior surface of the agitator body about an arc of less than 360° providing at least one tuftless gap of between about 10° and about 50° in arc. When the rotary agitator is de-energized for bare floor cleaning, the agitator comes to rest with the tuftless gap adjacent the floor being cleaned. Due to the fact that the tuftless gap ensures that there are no bristle tufts extending in an orthogonal direction between the agitator and the underlying floor, the weight of the vacuum cleaner and the force of the suction provided by the vacuum cleaner combine to produce a lowering of the nozzle assembly of the vacuum cleaner relative to the floor. This reduces the space between the bottom of the nozzle assembly and the floor which in turn increases the velocity of the suction air stream. The increased air velocity improves the ability of the air stream to entrain dirt and debris which is then sucked into the suction inlet of the vacuum cleaner so as to provide more efficient and effective bare floor cleaning.

SUMMARY OF THE INVENTION

In accordance with the purposes of the present invention as described herein, a rotary agitator is provided. The rotary agitator comprises a body having an exterior surface. A plurality of bristle tufts extend from the exterior surface of the body about an arc of less than 360° thereby providing at least one tuftless gap of between about 10° and about 50° in arc. The plurality of bristle tufts may be provided in a helical pattern, in a chevron pattern, in an offset chevron pattern, randomly or in any other arrangement so long as the tuftless gap is maintained.

In one particularly useful embodiment the bristle tufts are provided in two helical rows wherein each of the two helical rows extends along an arc of between about 140° to about 160° along opposing positions of the agitator body so as to provide two opposed tuftless gaps wherein each of the two tuftless gaps extends along an arc of between about 40° and about 20°.

In accordance with yet another aspect of the present invention a method for enhancing bare floor cleaning efficiency of a vacuum cleaner is provided. That method comprises providing the vacuum cleaner with a rotary agitator having a body with an exterior surface, a plurality of bristle tufts extending outwardly from that exterior surface about an arc of less than 360° and a tuftless gap on the exterior surface extending through an arc of about 10° and about 50°. When the rotary agitator is stopped for bare floor cleaning, the tuftless gap is adjacent the floor. The weight and suction of the vacuum cleaner produces a lowering of the nozzle assembly of the vacuum cleaner toward the floor being cleaned. This effectively reduces the space between the bottom of the vacuum cleaner and the floor. This likewise reduces the cross section through which the suction air stream travels thereby increasing the speed of the airstream being drawn into the vacuum cleaner. This provides an air stream more capable of entraining dirt and debris for more efficient and effective bare floor cleaning.

In the following description there is shown and described several different embodiments of the invention, simply by way of illustration of some of the modes best suited to carry out the invention. As it will be realized, the invention is capable of other different embodiments and its several details are capable of modification in various, obvious aspects all without departing from the invention. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings incorporated herein and forming a part of the specification, illustrate several aspects of the present invention and together with the description serve to explain certain principles of the invention. In the drawings:

FIG. 1 is a perspective view of a rotary agitator constructed in accordance with the teachings of the present invention including two helical rows of bristle tufts;

FIG. 2 is an end elevational view of the rotary agitator of FIG. 1 illustrating two helical rows of bristle tufts extending through an arc of 160° and two opposed tuftless gaps each extending through an arc of 20°;

FIG. 3 is an end elevational view similar to FIG. 2 but showing an alternative embodiment wherein the two helical rows of bristle tufts extend through an arc of 140° each and the two opposed tuftless gaps extend through an arc of 40° each;

FIGS. 4 a and 4 b are perspective views of an alternative embodiment of the present invention wherein two bristle tuft rows are each provided in a chevron pattern and two opposed tuftless gaps each extend through an arc of 30°;

FIGS. 5 a and 5 b are perspective views illustrating an alternative embodiment of the present invention wherein the agitator body includes two rows of bristle tufts both provided in an offset chevron pattern and two tuftless gaps therebetween;

FIGS. 6 a and 6 b are respective end elevational views of (a) a prior art agitator including two helical rows of bristle tufts wherein each row extends through an arc of 180° so as to provide bristle tufts around the full 360° arc of the agitator and (b) the rotary agitator of the present invention including two helical rows of bristle tufts as illustrated above in FIGS. 1 and 2. These figures illustrate how the rotary agitator of the present invention allows the nozzle assembly to more closely hug the floor and thereby increase the air stream velocity to produce enhanced cleaning efficiency; and

FIG. 7 is an end elevational view illustrating a prior art rotary agitator including two bristle tuft rows wherein each row extends along an arc of 180° so as to provide bristle tufts around the full 360° arc of the rotary agitator.

Reference will now be made in detail to the present preferred embodiment of the invention, examples of which are illustrated in the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

Reference is now made to FIGS. 1 and 2 illustrating one possible embodiment of the rotary agitator 10 of the present invention. In the illustrated embodiment, the rotary agitator 10 comprises a tubular body 12 having an exterior surface 14. A plurality of bristle tufts 16 extend or project from the exterior surface 14 of the body 12 about an arc of less than 360° thereby providing at least one tuftless gap 18 of between about 10° to about 50° along the exterior surface 14.

In the embodiment particularly illustrated in FIGS. 1 and 2, the bristle tufts 16 are provided in two, opposed helical rows 20, 22 with each row extending through an arc of approximately 160°. This creates two opposed tuftless gaps 18 with each such gap extending through an arc of about 20° (see particularly FIG. 2 showing one tuftless gap 18 between two rows 20, 22, the other gap being hidden on the opposite side of the agitator).

In the alternative embodiment illustrated in FIG. 3, the bristle tufts 16 extend through two opposed helical rows 24, 26 each having an arc of 140°. This produces two opposed tuftless gaps 28 each having an arc of 40°.

In yet another embodiment illustrated in FIGS. 4 a and 4 b, the bristle tufts 16 are provided in two rows 30, 32 wherein each row defines a chevron pattern. This produces two opposed tuftless gaps 34 wherein each of the gaps extends through an arc of between about 10° and about 50°.

In yet another embodiment illustrated in FIGS. 5 a and 5 b, the bristle tufts 16 are provided in two separate rows 36, 38 wherein each of the rows defines an offset chevron pattern. Two tuftless gaps 40 are provided between the rows 36, 38 and extend through an arc of between about 10° and about 50°.

While the rotary agitators 10 of the present invention are illustrated as having tubular bodies 12 with circular cross sections, it should be appreciated that the agitator bodies may also be of solid construction if desired. Further, the agitator bodies themselves do not have to be circular in cross section even though the arc described by the bristle tufts 16 is semi-circular in shape.

The agitator body 12 may be made from substantially any appropriate material including, but not limited to, plastic, metal, composite and/or wood. Similarly, the bristle tufts 16 may be made from substantially any appropriate material including, but not limited to, plastics such as nylon.

In accordance with an additional aspect of the present invention a method is provided for enhancing the bare floor cleaning efficiency of a vacuum cleaner. The method comprises providing the vacuum cleaner with a rotary agitator 10 having a body 12 with an exterior surface 14, a plurality of bristle tufts 16 extending outwardly from the exterior surface about an arc of less than 360° and a tuftless gap 18 on the exterior surface extending through an arc of about 10° and about 50°.

Most vacuum cleaners manufactured today include a switch for de-energizing the rotary agitator 10 during bare floor cleaning. This is because the air turbulence generated by the bristle tufts of the rapidly rotating agitator can interfere with the cleaning efficiency of a vacuum cleaner when attempting to clean a bare floor. More specifically, the turbulence can push dirt and debris away from the suction inlet.

When a vacuum cleaner equipped with the rotary agitator 10 of the present invention is de-energized, that rotary agitator will stop with a tuftless gap 18 adjacent to the floor F being cleaned (see FIG. 6 a). This is because the absence of tufts in the gap 18 causes the gap to be least resistant to stopping in the bottom dead center position. When in this position, no bristle tufts 18 are orthogonal to the floor. Accordingly, the bristle tufts 16 bend much more easily and the weight of the vacuum cleaner and the force of the suction being generated combine to draw the nozzle assembly N of the vacuum cleaner toward the floor F. This reduces the height or space H₂ between the bottom B of the nozzle assembly N and the floor F. Accordingly, the cross sectional area through which the vacuum air stream flows is reduced. This results in an increase in air velocity toward the suction inlet S of the vacuum cleaner. The increased air velocity more efficiently and effectively entrains dirt and debris which is drawn into the suction inlet S of the vacuum cleaner thereby enhancing bare floor cleaning efficiency (see action arrows A).

As best illustrated in FIG. 6 b, such an efficiency enhancement is not provided when the same vacuum cleaner nozzle N is fitted with an agitator R of prior art design incorporating two opposing rows of bristle tufts T wherein each row extends through an arc of 180° so as to provide bristle tufts extending from the body of the agitator R through a full 360° arc of the agitator. Such a bristle tuft arrangement effectively presents at least one bristle tuft T orthogonal to the floor F in any position of the rotary agitator R. Bristle tufts T in such a substantially orthogonal position resist bending. Accordingly, the bristle tufts T resist any significant lowering of the nozzle assembly due to the weight of the vacuum cleaner and the suction air stream. Thus, for bristle tufts T of the same height, the prior art agitator R supports the bottom B of the nozzle assembly N at a height H₁ above the floor F. This is substantially higher than the height H₂ discussed above and illustrated in FIG. 6 a. Accordingly, with the prior art agitator R there is no lowering of the height/narrowing of the space between the bottom B of the nozzle assembly N and the floor F and no increase in air stream velocity to provide enhanced cleaning action.

The foregoing description of the preferred embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. For example, while the rotary agitator 10 of the present invention is described above as having two rows of bristle tufts 16, substantially any number of rows may be provided so long as a tuftless gap 18 of appropriate arc is provided. Similarly, the rotary agitator 10 may alternatively include only randomly spaced bristle tufts 16 so long as a tuftless gap 18 of appropriate arc is provided.

The embodiments were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled. The drawings and preferred embodiments do not and are not intended to limit the ordinary meaning of the claims in their fair and broad interpretation in any way. 

1. A rotary agitator, comprising: a body having an exterior surface; a plurality of bristle tufts extending from said exterior surface of said body about an arc of less than 360° thereby providing at least one tuftless gap of between about 10° and about 50° in arc.
 2. The agitator of claim 1, wherein said plurality of bristle tufts are provided in a helical pattern.
 3. The agitator of claim 1, wherein said plurality of bristle tufts are provided in a chevron pattern.
 4. The agitator of claim 1, wherein said plurality of bristle tufts are provided in an offset chevron pattern.
 5. The agitator of claim 1, wherein said plurality of bristle tufts are provided in two helical patterns wherein each of said two helical patterns extends along an arc of between about 140° to about 160° along opposing positions of said body so as to provide two opposed tuftless gaps wherein each of said two tuftless gaps extends along an arc of between about 40° and about 20°.
 6. The agitator of claim 1, wherein said body is made from a plastic material.
 7. The agitator of claim 1, wherein said body is made from a metal material.
 8. The agitator of claim 1, wherein said body is made from a composite material.
 9. The agitator of claim 1, wherein said body is made from a wood material.
 10. A rotary agitator, comprising: a body having an exterior surface; a plurality of bristle tufts extending outwardly from said exterior surface about an arc of less than 360°; a tuftless gap on said exterior surface to provide for enhanced bare floor cleaning.
 11. The agitator of claim 10, wherein said tuftless gap extends through an arc of between about 10° and about 50°.
 12. The agitator of claim 10, wherein said tuftless gap extends through an arc of between about 20° and about 40°.
 13. The agitator of claim 12, further including a second tuftless gap extending through an arc of between about 20° and about 40°.
 14. The agitator of claim 13, wherein said second tuftless gap is provided opposite said tuftless gap.
 15. A method for enhancing bare floor cleaning efficiency of a vacuum cleaner comprising: providing said vacuum cleaner with a rotary agitator having a body with an exterior surface, a plurality of bristle tufts extending outwardly from said exterior surface about an arc of less than 360° and a tuftless gap on said exterior surface extending through an arc of between about 10° and about 50° whereby when said rotary agitator is stopped for bare floor cleaning, said tuftless gap is adjacent said floor and weight and suction of said vacuum cleaner lowers a nozzle assembly of said vacuum cleaner toward a floor being cleaned thereby reducing space between a bottom of said vacuum cleaner and said floor and increasing speed of an airstream being drawn into said vacuum cleaner so as to provide more efficient and effective bare floor cleaning. 